There has heretofore been known an electrostatic printing apparatus for attaching powdery ink onto a surface of an object by using an electrostatic force to print a printed pattern including characters and figures on the surface of the object. A conventional electrostatic printing apparatus can perform printing only with one-colored powdery ink. Therefore, when multicolored printing is to be performed on an object, it is necessary to provide the same number of electrostatic printing apparatuses as the number of colors to be used.
FIG. 41 is a vertical cross-sectional view showing an arrangement of a conventional electrostatic printing apparatus for performing three-colored printing. In an example shown in FIG. 41, an electrostatic printing apparatus 500a first performs printing with a first color, and then a pallet 550 having an object 1 placed thereon is transferred to the next electrostatic printing apparatus 500b. The electrostatic printing apparatus 500b performs printing with a second color. After the electrostatic printing apparatus 500b performs printing with the second color, the pallet 550 is further transferred to the next electrostatic printing apparatus 500c, which performs printing with a third color. Thus, when multicolored printing is to be performed with use of a conventional electrostatic printing apparatus, it is necessary to provide a plurality of electrostatic printing apparatuses and to perform printing with each color in each electrostatic printing apparatus.
As described above, when multicolored printing is to be performed with use of a conventional electrostatic printing apparatus, it is necessary to provide the same number of electrostatic printing apparatuses as the number of colors to be used. Therefore, a wide space is required for installing the apparatuses, and cost is highly increased to perform multicolored printing.
Further, when a pallet having an object placed thereon is transferred to the next electrostatic printing apparatus, the pallet may get out of position with respect to a screen, or the object may get out of position in the pallet by vibration or shock during transferring. In such a case, printing positions become different according to colors, and hence accurate and clean printing cannot be performed on the object.
FIG. 42 is a schematic diagram showing an arrangement of a conventional electrostatic printing apparatus. The conventional electrostatic printing apparatus has a stencil screen 610 disposed above an object 600, a rotation brush 620 on the screen 610, and a hopper 640 for supplying powdery ink 630 onto the brush 620. A printed pattern including characters and figures is formed of a mesh 611 on the screen.
The powdery ink 630 supplied from the hopper 640 is pushed out downwardly through the mesh 611 of the screen 610 by rotation of the brush 620. A high direct-current voltage is applied between the object 600 and the screen 610 by a direct-current power supply DC to form an electrostatic field between the object 600 and the screen 610. The powdery ink which has passed through the mesh 611 and has thus been charged travels straight toward the object 600, which serves as a counter electrode, in the electrostatic field and is attached to a surface of the object 600. Thus, a printed pattern in the screen 610 which includes characters and figures is printed on the surface of the object 600.
However, in the conventional electrostatic printing apparatus, when printing is to be performed continuously on a plurality of objects, each object 600 needs to be disposed below the screen 610 before printing. Therefore, processing time required before printing becomes long, and a printing process becomes troublesome. Thus, the conventional electrostatic printing apparatus cannot practically perform continuous printing.
Incidentally, as shown in FIG. 43, when a mold releasing agent or other edible powder is applied onto a food molding receptacle, edible powder 710 is dropped from above the food molding receptacle by shaking a screen 700 having a mesh in a lattice pattern and is attached to inner surfaces of the molding receptacle 720.
However, it is difficult to attach the edible powder 710 to side surfaces or inclined surfaces of the molding receptacle 720 by using the screen 700. Thus, the edible powder 710 is dropped onto a bottom of the molding receptacle and accumulated thereon. Further, since the edible powder 710 needs to be dropped through the screen 700, powder having a relatively large particle diameter should be selected as the edible powder 710. However, since powder having a large particle diameter has a large weight, the powder is unlikely to be attached to side surfaces of the molding receptacle 720 in particular and is likely to be dropped onto a bottom of the molding receptacle 720 by its weight and accumulated thereon. Thus, it is difficult to apply the edible powder 710 uniformly onto inner surfaces of the molding receptacle 720. Even if the edible powder 710 can be attached to the side surfaces of the molding receptacle 720, the edible powder 710 is likely to be detached by small shock and dropped onto the bottom because the edible powder 710 has a small adhesive strength when the screen 700 is used to apply the edible powder 710. Further, when the screen 700 is employed to apply the edible powder 710, the edible powder 710 is dropped not only to the inside of the molding receptacle 720, but also to the outside of the molding receptacle 720 because the screen 700 is shaken. Thus, the conventional electrostatic printing apparatus consumes the edible powder uselessly.
Further, in addition to the aforementioned method using a screen, as shown in FIG. 44, when edible powder is to be applied onto surfaces of molded foods, molded foods 810 and edible powder 820 are introduced into a rotation drum 800, and then the rotation drum 800 is rotated to attach the edible powder 820 onto surfaces of the molded foods 810. However, when the rotation drum 800 is rotated, the foods 800 are brought into contact with each other and lose their shapes, so that commercial values of the foods are lowered.
In order to season a food, seasoning is usually added to the food during processing the food in the following manners. Seasoning is mixed with a food, and the food is kneaded. Liquid seasoning is sprinkled and added onto a surface of a food. Alternatively, powdery seasoning is applied on a surface of a food with use of the aforementioned screen.
However, in a case where seasoning is mixed with and added to a food, if the food with which the seasoning is mixed is subjected to a heating process or the like, then functions and flavor of the seasoning may be spoiled by heating. Generally, natural pigment or the like is weak to heat and may be discolored during the heating process.
In a case where seasoning is sprinkled and added onto a surface of a food, liquid seasoning is generally used. However, if such liquid seasoning is applied to some kinds of foods, then flavor and mouthfeel of the foods may be spoiled under the influence of moisture in the liquid seasoning. For example, if liquid seasoning is applied tofu or dried layer, then a food body is melted by moisture, so that the food loses its original functions.
For example, when powder such as cocoa powder is applied onto a surface of a semi-solid such as pudding or jelly with use of a screen, because the powder has a small adhesive strength, the cocoa powder applied to the surface of the food may be detached by shock during transportation of the food, or the detached cocoa powder may be solidified, so that taste and beauty of the food may be spoiled.
There has been attempted to apply liquid edible ink onto an edible sheet by letterpress printing, then place the edible sheet on a food and transcribe a pattern printed of the edible sheet to the food. When an edible sheet is placed on a surface of a food having moisture, the edible sheet is melted on the surface of the food by moisture to thus transcribe a pattern printed by liquid ink to the surface of the food.
However, since this method employs liquid edible ink, it is necessary to thicken dough of the edible sheet or to provide water resistance with the sheet in order to maintain resistance to moisture of the ink during printing. A food to which a pattern is transcribed by using such an edible sheet has spoiled taste and mouthfeel.
In order to form a food, it has heretofore been necessary to pour a material into a mold or to manually make a shape of a food. Thus, much labor is required to form a food. For example, bekkou candy is produced as follows. Boiled sugar is dropped from a nozzle with a certain pattern onto an iron plate and then cooled to solidify the sugar. The solidified sugar is separated from the iron plate to obtain bekkou candy. Skill to a certain degree has been required to produce such a molded food. Further, when fresh cream is decorated on a sponge cake to produce a fancy cake, a clean fancy cake cannot be produced by those who are not a skilled worker.